U.S. patent number 5,406,860 [Application Number 08/160,545] was granted by the patent office on 1995-04-18 for transmission shift lever assembly.
This patent grant is currently assigned to Deere & Company. Invention is credited to David J. Easton, Howard T. Uehle.
United States Patent |
5,406,860 |
Easton , et al. |
April 18, 1995 |
Transmission shift lever assembly
Abstract
A lever assembly includes a lever pivotally coupled to a housing
for movement in a fore-and-aft direction and in a transverse
direction. A guide plate is fixed to an end of the housing and has
a guide slot which receives the lever. The guide slot has a
fore-and-aft extending main slot. The guide slot also has first,
second and third fore-and-aft extending sub-slots spaced apart from
the main slot. Each of the sub-slots is connected with the main
slot by a transverse extending connecting slot. A sector member is
pivotally mounted between the housing and the lever. A first magnet
is mounted on the lever. A second magnet is mounted on the sector
member. Hall effect sensors are mounted on the housing. The sector
member, the magnets and the Hall effect sensors cooperate so that
signals are generated representing the position of the lever within
the guide slot. A lever return spring is biased to urge the lever
towards an aft end of the main slot. A transverse return spring is
biased to urge the lever towards the sector member. A centering
spring is biased to urge the sector member towards a centered
position. Detent mechanisms operate to releasably maintain the
lever within the sub-slots.
Inventors: |
Easton; David J. (Cedar Falls,
IA), Uehle; Howard T. (Cedar Falls, IA) |
Assignee: |
Deere & Company (Moline,
IL)
|
Family
ID: |
22577326 |
Appl.
No.: |
08/160,545 |
Filed: |
December 1, 1993 |
Current U.S.
Class: |
74/335;
74/473.33 |
Current CPC
Class: |
F16H
59/02 (20130101); G05G 5/20 (20130101); F16H
59/044 (20130101); F16H 59/105 (20130101); F16H
2059/026 (20130101); Y10T 74/20159 (20150115); Y10T
74/19251 (20150115) |
Current International
Class: |
F16H
59/02 (20060101); G05G 5/20 (20060101); G05G
5/00 (20060101); F16H 61/70 (20060101); F16H
59/10 (20060101); F16H 59/04 (20060101); F16H
059/02 () |
Field of
Search: |
;74/335,473R,475,522,536
;192/4A ;180/332,333,336 ;D12/179 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
John Deere Literature "Big Power Efficiency". .
Agco White Literature, 6100 Series Tractors. .
Ford New Holland Literature, 8030 Series Tractors. .
Literature on John Deere 7000 Series Power Shift Transmission
Controls. .
Champion Road Machinery, 700 Series Motor Grader, Operator's
Manual, Sep. 1987..
|
Primary Examiner: Marmor; Charles A.
Assistant Examiner: Kim; Chong H.
Claims
What is claimed is:
1. A control lever assembly for generating control signals for
controlling a powershift transmission, the control lever assembly
having a housing, a lever pivotally coupled to the housing, a lever
guide with a slot which slidably receives the lever and which
constrains the lever to move within a defined path, and signal
generators for generating signals representing the positions of the
lever within the slot, the improvement wherein:
the slot comprises a main slot extending in a first direction, a
first sub-slot spaced apart from the main slot and extending
parallel to said first direction, a second sub-slot spaced apart
from the main slot and extending parallel to said first direction,
a third sub-slot spaced apart from the main slot and extending
parallel to said first direction, each of the sub-slots being
connected with the main slot by a corresponding first, second and
third connecting slot extending transverse to said first
direction;
the first connecting slot opening into a central portion of the
first sub-slot;
the second connecting slot opening into a central portion of the
second sub-slot;
the third connecting slot opening into an end portion of the third
sub-slot; and
the third sub-slot extends from said end portion towards the first
and second sub-slots.
2. The control lever assembly of claim 1, wherein:
the sub-slots are arranged in an array which substantially parallel
to the main slot.
3. The control lever assembly of claim 1, wherein:
each sub-slot has a length which is shorter than the length of the
main slot.
4. The control lever assembly of claim 1, wherein:
the first connecting slot opens into a central portion of the first
sub-slot;
the second connecting slot opens into a central portion of the
second sub-slot; and
the third connecting slot opens into an end portion of the third
sub-slot.
5. The control lever assembly of claim 1, wherein:
the second sub-slot is located between the first and third
sub-slots.
6. A control lever assembly for generating control signals for
controlling a powershift transmission, the control lever assembly
having a housing, a lever pivotally coupled to the housing, a lever
guide with a slot which slidably receives the lever and which
constrains the lever to move within a defined path, and signal
generators for generating signals representing the positions of the
lever within the slot, the improvement wherein:
the slot comprises a main slot extending in a first direction, a
first sub-slot spaced apart from the main slot and extending
parallel to said first direction, a second sub-slot spaced apart
from the main slot and extending parallel to said first direction,
a third sub-slot spaced apart from the main slot and extending
parallel to said first direction, each of the sub-slots being
connected with the main slot by a corresponding first, second and
third connecting slot extending transverse to said first
direction;
the first connecting slot opening into a central portion of the
first sub-slot;
the second connecting slot opening into a central portion of the
second sub-slot;
the third connecting slot opening into an end portion of the third
sub-slot;
the second sub-slot is located between the first and third
sub-slots; and
the third sub-slot extending from said end portion towards the
second sub-slot.
7. A control lever assembly for a powershift transmission, the
control lever assembly comprising:
a housing, the housing having a side wall and a guide plate, the
guide plate having a guide slot formed therein;
a lever member coupled to the housing for movement in a first
direction and for movement in a second direction orthogonal to the
first direction, the lever being slidably received by the guide
slot;
a first position indicating element carried by the lever
member;
a sector member rotatably mounted in the housing between the side
wall and the lever member, the sector member having a first side
facing the lever member and a second side facing the side wall, the
sector member having a plurality of apertures arranged along a
plane which is parallel to said first direction, the lever member
being pivotal in the first direction to move the first position
indicating element into registry with each of the apertures, the
lever member being pivotal in the second direction to move the
first position indicating element into and out of the apertures,
and the sector member and the lever member being pivotal together
in the first direction when the first position indicating element
is received by one of the apertures;
a second position indicating element carried on the second side of
the sector member;
a plurality of sensors fixed to the side wall, each sensor being in
registry with a corresponding one of the apertures, the sensors
being responsive to proximity of the first position indicating
element, each sensor generating a signal indicative of the first
position indicating element being received by the corresponding
aperture;
a plurality of signal generators fixed to the side wall and
arranged in a plane which is parallel to said first direction, the
plurality of signal generators being responsive to proximity of the
second position indicating element and generating signals in
response to pivoting of the sector member.
8. The control lever assembly of claim 7, wherein:
the plurality of apertures comprises first, second and third
apertures; and
the plurality of signal generators comprises first, second and
third signal generators.
9. The control lever assembly of claim 7, wherein:
the guide slot comprises a main slot extending in the first
direction, a first sub-slot spaced apart from the main slot and
extending parallel to said first direction, a second sub-slot
spaced apart from the main slot and extending parallel to said
first direction, a third sub-slot spaced apart from the main slot
and extending parallel to said first direction, each of the
sub-slots being connected with the main slot by a corresponding
first, second and third connecting slot extending parallel to said
second direction.
10. The control lever assembly of claim 9, further comprising:
a lever return spring coupled to lever member and biased to urge
the lever member towards an end of the main slot.
11. The control lever assembly of claim 7, further comprising:
a transverse return spring coupled to the lever member and biased
to urge the lever member towards the sector member.
12. The control lever assembly of claim 7, further comprising:
a centering spring coupled to the sector member and biased to urge
the sector member towards a centered position.
13. A control lever assembly for a powershift transmission, the
control lever assembly comprising:
a housing having an opening at a first end and a bore near a second
end;
a shaft rotatably received in the bore;
an arm coupled to the shaft and extending generally radially
therefrom;
a lever member pivotally coupled to the arm and pivotal about a
pivot pin which is perpendicular to an axis of the shaft, the lever
being movable in a first direction about the shaft and movable in a
second direction about the pivot pin;
a stub member projecting from the lever member and spaced radially
from the shaft;
a first position indicating element carried by the stub member;
a guide plate fixed to the first end of the housing, the guide
plate having a guide slot which receives the lever member, the
guide slot comprising a main slot extending in a first direction, a
first sub-slot spaced apart from the main slot and extending
parallel to said first direction, a second sub-slot spaced apart
from the main slot and extending parallel to said first direction,
a third sub-slot spaced apart from the main slot and extending
parallel to said first direction, each of the sub-slots being
connected with the main slot by a corresponding first, second and
third connecting slot extending transverse to said first
direction;
a sector member rotatably mounted on the shaft and positioned
between the housing and the lever member, the sector member having
a first side facing the lever member and a second side facing the
housing, the sector member having first, second and third apertures
spaced radially apart from the shaft and arranged in an array which
extends parallel to said first direction, the lever member being
pivotal about the shaft to move the stub member into registry with
each of the apertures, and the lever member being pivotal about the
pivot pin to move the stub member into and out of the
apertures;
a second position indicating element carried on the second side of
the sector member;
a first sensor fixed with respect to the housing in registry with
the first aperture;
a second sensor fixed with respect to the housing in registry with
the second aperture;
a third sensor fixed with respect to the housing in registry with
the third aperture, the first, second and third sensors being
responsive to proximity of the first position indicating element,
the first sensor generating a signal indicative of the first
position indicating element being received-by the first aperture
and the lever member being received by the first sub-slot, the
second sensor generating a signal indicative of the first position
indicating element being received by the second aperture and the
lever member being received by the second sub-slot, and the third
sensor generating a signal indicative of the first position
indicating element being received by the third aperture and the
lever member being received by the third sub-slot;
a plurality of signal generators fixed with respect to the housing
and arranged in an array which is parallel to said first direction,
the plurality of signal generators being responsive to proximity of
the second position indicating element and generating signals in
response to pivoting of the lever member and the sector member
about the pivot shaft when the stub member is received in one of
the apertures and the lever member is received by one of the
sub-slots.
14. The control lever assembly of claim 13, wherein:
the sub-slots are arranged in an array which is substantially
parallel to the main slot.
15. The control lever assembly of claim 13, further comprising:
a lever return spring coupled to the arm and biased to urge the arm
and the lever member towards an end of the main slot.
16. The control lever assembly of claim 13, further comprising:
a transverse return spring coupled to the lever member and biased
to urge the lever member towards the sector member.
17. The control lever assembly of claim 13, further comprising:
a centering spring coupled to the sector member and biased to urge
the sector member towards a centered position.
18. The control lever assembly of claim 13, further comprising:
a plurality of detent mechanisms, each detent mechanism operation
to releasably maintain the stub member within a corresponding one
of the apertures.
19. The control lever assembly of claim 18, wherein each detent
mechanism comprises:
a ramp member projecting from the sector member near a
corresponding one of the apertures; and
a detent spring mounted on the lever member and having an arm which
slidably engages the ramp member.
20. The control lever assembly of claim 13, further comprising:
a slot detent spring mounted on the housing and engageable with the
lever and biased to releasably hold the lever in a desired position
in one of the sub-slots.
21. The control lever assembly of claim 13, wherein:
the first and second position indicating elements are comprised of
permanent magnets; and
the sensors are comprised of Hall effect elements.
22. A control lever assembly for generating control signals for
controlling a powershift transmission, the control lever assembly
having a housing, a lever pivotally coupled to the housing, a lever
guide with a slot which slidably receives the lever and which
constrains the lever to move within a defined path, and signal
generators for generating signals representing the positions of the
lever within the slot, the slot including a forward slot and a park
slot, the improvement wherein:
one of said signal generators is actuated when the lever is in the
forward slot and when the lever is in the park slot; and
the forward slot and the park slot are spaced apart in an
end-to-end manner.
23. The control lever assembly of claim 22, further comprising:
a further signal generator which is actuated when the lever enters
one end of the park slot, said one of said signal generators being
actuated when the lever is moved to another end of the park
slot.
24. The control lever assembly of claim 22, wherein:
both the forward slot and the park slot extend in a direction
parallel to a first direction.
25. A control lever assembly for generating control signals for
controlling a powershift transmission, the control lever assembly
having a housing, a lever pivotally coupled to the housing, a lever
guide with a slot which slidably receives the lever and which
constrains the lever to move within a defined path, and signal
generators for generating signals representing the positions of the
lever within the slot, the improvement wherein:
the slot comprises a main slot extending in a first direction, a
first sub-slot spaced apart from the main slot and extending
parallel to said first direction, a second sub-slot spaced apart
from the main slot and extending parallel to said first direction,
a third sub-slot spaced apart from the main slot and extending
parallel to said first direction, each of the sub-slots being
connected with the main slot by a corresponding first, second and
third connecting slot extending transverse to said first direction;
and
the sub-slots are spaced apart in an end-to-end manner and are
arranged in an array which is substantially parallel to the main
slot.
26. A control lever assembly for generating control signals for
controlling a powershift transmission, the control lever assembly
having a housing, a lever pivotally coupled to the housing, a lever
guide with a slot which slidably receives the lever and which
constrains the lever to move within a defined path, and signal
generators for generating signals representing the positions of the
lever within the slot, the improvement wherein the slot
comprises:
a main slot extending in a first direction;
a first sub-slot spaced apart from the main slot and extending
parallel to said first direction;
a second sub-slot spaced apart from the main slot and extending
parallel to said first direction;
a third sub-slot spaced apart from the main slot and extending
parallel to said first direction, the sub-slots being spaced apart
from each other in an end-to-end manner;
a first connecting slot connecting the first sub-slot with one end
of the main slot;
a second connecting slot connecting the second sub-slot with a
central part of the main slot;
a third connecting slot connecting the third sub-slot with another
end of the main slot.
Description
BACKGROUND OF THE INVENTION
The invention relates to a control lever assembly, and more
particularly, to a control lever assembly for a powershift
transmission shift control which operates in a "pulse" or "bump
shift" manner.
Electronically controlled powershift transmissions require an
operator control device, such as one or two shift levers, which
generate control signals which are utilized to control the
transmission. For example, U.S. Pat. No. 4,425,620, issued 10 Jan.
1984 to Batcheller et al., and U.S. Pat. No. 4,855,913, issued 8
Aug. 1989 to Brekkestran et al., both show transmissions controlled
in response to two levers: a mode lever and a pulser or
upshift/downshift lever. Also, a powershift transmission with two
control levers is provided on a 700 Series Motor Grader
manufactured by Champion Road Machinery.
Various designs have been proposed whereby a single lever performs
both the mode selecting and the upshift/downshift functions. For
example, a single lever shift control is available on the 8030
Series Tractor manufactured by Ford-New Holland. In this single
lever design, the lever is movable fore-and-aft to forward, neutral
and reverse positions, and the lever is movable laterally from each
of the forward, neutral and reverse positions to upshift and
downshift sub-positions. However, this design provides no park
position and the park function is accomplished with a separate
device. Also, this design requires that a locking ring mounted on
the lever be lifted to move the lever forward and backward from its
neutral position.
Also, U.S. Pat. No. 4,442,730 issued 17 April 1984 to Snoy, shows a
transmission controlled in response to a single lever movable
between forward, neutral and reverse positions and movable
laterally from the forward and reverse positions to upshift and
downshift positions. U.S. Pat. No. 4,991,454 issued 12 Feb. 1991 to
Bulgrien, shows a pattern for a transmission shift control lever
wherein the pattern includes forward, neutral and reverse positions
and the lever is movable from each of the forward, neutral and
reverse positions to upshift and downshift sub-positions. U.S. Pat.
No. 4,926,172 issued 15 May 1990 to Gorsek and U.S. Pat. No.
5,243,871 issued 14 Sep. 1993 to Weiten, both show lever mechanisms
with a guide which defines a shift pattern similar to the pattern
described in the Bulgrien patent. In these single lever designs,
the upshift/downshift function requires movement of the lever in
directions which are transverse to the direction of movement which
performs the mode selecting function.
A different single lever shift control is available on the 6100
Series Tractor manufactured by Agco White. In this single lever
design, there is a single linear fore-and-aft extending
forward-neutral-reverse slot with forward upshift, noshift and
downshift positions at a forward end of the slot and reverse
upshift, noshift and downshift positions at an aft end of the slot.
However, this design provides no park position and the park
function is accomplished with a separate lever. Also, this design
requires that a separate push button mounted on the top of the
lever be depressed to move the lever out of its neutral position.
Such a lever shift control is complicated to operate and there is
no "race track" lever path which clearly indicates the shift
functions being performed.
It would be desirable to have a single lever type shift control
lever which performs both the forward-neutral-reverse mode
selecting function and the upshift/downshift function in response
to natural or intuitive lever motions, which includes a park
position and which does not require a push button or a locking
ring.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to provide a
transmission shift control lever which permits the mode selecting
function and the upshift/downshift function to be performed with a
natural or intuitive movement of a lever.
A further object of the invention is to provide such a transmission
control lever which permits the mode selecting function to be
performed with movement in a fore-and-aft direction and which
permits the upshift/downshift function to be performed with
movement in a fore-and-aft direction.
A further object of the invention is to provide such a transmission
control lever which includes a park position.
A further object of the invention is to provide such a transmission
control lever which does not require a push button or a locking
ring.
These and other objects are achieved by the present invention,
wherein a lever assembly includes a lever pivotally coupled to a
housing for movement in a fore-and-aft direction and in a
transverse direction. A guide plate is fixed to an end of the
housing and has a guide slot which receives the lever. The guide
slot has a fore-and-aft extending main slot. The guide slot also
has first, second and third fore-and-aft extending sub-slots spaced
apart from the main slot and arranged in an array on one side of
the main slot. Each of the sub-slots is connected with the main
slot by a transverse extending connecting slot. A sector member is
pivotally mounted between the housing and the lever. A first magnet
is mounted on the lever. A second magnet is mounted on the sector
member. Hall effect sensors are mounted on the housing. The sector
member, the magnets and the Hall effect sensors cooperate so that
signals are generated representing the position of the lever within
the guide slot. A lever return spring is biased to urge the lever
towards an aft end of the main slot. A transverse return spring is
biased to urge the lever towards the sector member. A centering
spring is biased to urge the sector member towards a centered
position. Detent mechanisms operate to releasably maintain the
lever within the sub-slots.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side assembly view of the lever assembly of the present
invention;
FIG. 2 is a top assembly view of the lever assembly of the present
invention;
FIGS. 3A and 3B together form an exploded view of the lever
assembly of the present invention from one perspective.
FIGS. 4A and 4B together form an exploded view of the lever
assembly of the present invention from another perspective.
DETAILED DESCRIPTION
The control lever assembly 10 includes a housing 12 forming a wall
14 and a rim 16. The wall 14 has a bore 18 which is formed near a
lower end thereof and a curved opening 20 spaced radially from the
bore 18. Located radially below the opening 20 is a curved
centering spring slot 21. The control lever assembly 10 is intended
for use with an electronically controlled powershift transmission,
such as is commercially available from various manufacturers.
A guide plate 22 is fixed to an upper end of the housing 12. A
guide slot 24 is formed in the guide plate 22. The guide slot 24
includes a relatively long fore-and-aft extending main slot portion
26. The guide slot 24 also includes a fore-and-aft extending
forward upshift/downshift slot 28, a fore-and-aft extending reverse
upshift/downshift slot 30 and a forwardly extending park slot 32.
Slots 28, 30 and 32 are shorter than the main slot 26, and are
spaced transversely apart from the main slot 26. Slots 28 and 30
are connected with main slot 26 by a corresponding one of
transverse extending connecting slots 34 and 36, respectively. Park
slot 32 is connected with main slot 26 by a transverse extending
neutral slot 38. The housing 12 forms a switch enclosure 31 on one
side thereof. A commercially available snap action switch 33 is
mounted in the enclosure 31. The snap action switch 33 is used
preferably as a neutral start switch, such as described in U.S.
Pat. No. 5,251,733 issued 12 Oct. 1993, (attorney's docket No.
14090), and which is hereby incorporated by reference.
A pivot member 40 includes a shaft 42 which is rotatably received
by the bore 18 and an arm 44 which extends radially from an end of
the shaft 42. The arm 44 is formed by a pair of generally parallel
sides 46 and 48 which form a slot 50 therebetween. An end portion
52 of the arm 44 extends parallel to the axis of shaft 42 and
towards the plate 14. A slot 53 is formed in the end portion 52. A
pivot bore 54 extends through the sides 46 and 48 near the shaft
42. An arm 56 projects from side 46 for engagement with the neutral
start switch 33.
A lever 60 is pivotally coupled to arm 44 by a pivot pin 62 which
extends through a forked portion 64 of lever 60 and through the
bore 54. The lever 60 includes a shaft 66 which is movable within
the guide slot 24 and which extends from forked portion 64 to a
handle 67 for grasping by an operator. The shaft 66 carries a
magnet carrier 68 which projects toward the housing wall 14 from a
central portion of the shaft 66. As best seen in FIG. 3B, a
permanent magnet 70 is mounted in the magnet carrier 68. As a
result, the lever 60 is movable in a fore-and-aft direction about
the axis of shaft 42 and is movable transversely about the axis of
pin 62. A detent spring 72 has a pair of arms which extend between
a pair of coils which are held by a pin 74 on the shaft 66 between
forked portion 64 and magnet carrier 68.
A sector member 80 is positioned between the lever 60 and the wall
14. The sector member 80 has a generally fan-shaped body 81
partially surrounded by a rim 83. A pair of arcuate reinforcing
ribs 85 and 87 extend across the body 81 from one side of the rim
83 to the other. A bore 78 extends through a lower end of sector
member 80 and rotatably receives the shaft 42. The sector member 80
has a first side facing the lever 60 and a second side facing the
wall 14. The sector member 80 has first, second and third sensor
apertures 82, 84 and 86 spaced radially apart from the shaft bore
78 and arranged in a curved array centered about the axis of bore
78.
Located radially inward of each sensor aperture is a corresponding
detent aperture 88, 90 and 92, respectively. A detent member 94, 96
and 98 projects from the lower edge of each detent aperture 88, 90
and 92, respectively. Each of the detent members 94, 96 and 98
forms a pair of ramp surfaces which slope downwardly and away from
a linearly extending apex which projects away from the axis of
shaft 42. The detent spring 72 is releasably engagable with the
detent members 94, 96 and 98 to releasably hold the lever 60 within
one of the slots 28, 30 or 32.
Located radially inward of the detent apertures is a curved
centering spring slot 100. A second permanent magnet 102 is held in
a recess 104 which is located radially above sensor aperture 84 on
the side of the sector member 80 which faces towards the wall 14.
Located radially inward of the rib 87 is a curved slot 106 for
receiving the end 52 of pivot member 40 in which is formed slot
53.
A circuit board 110 is fixed to the side of wall 14 opposite the
sector member 80 and radially above opening 20 and generally in
registry with the sensor apertures 82, 84, 86 and with magnet 102.
A set of Hall effect sensors or switches 120, 122, 124, 126, 128,
130, 132, 134 are mounted on the side of board 110 facing the
sector member 80. Sensors 120 and 122 are mounted in registry with
aperture 82 and are preferably used as forward and "not neutral"
switches, respectively. Sensors 124 and 126 are mounted in registry
with aperture 84 and are preferably used as "not neutral" and
reverse switches, respectively. Sensor 128 is mounted in registry
with aperture 86 and is preferably used as a park switch. Sensors
130, 132 and 134 are mounted in registry with the second magnet 102
and are preferably used as Bump shift, "no shift and bump shift"
switches, respectively. The circuit board 110 is protected by a
cover 140 which is bolted to the wall 14.
A lever return spring 142 has a coil mounted on the shaft 42, an
arm 144 which engages rim 83 of sector member 80 and an arm 146
which is received in slot 52 of the pivot member 40. Spring 142 is
biased to urge the lever 60 counterclockwise (viewing FIG. 1) with
respect to sector member 80.
A lateral return spring 150 has a coil mounted between sides 46 and
48 of pivot member 40, an arm 152 which engages part of pivot
member 40, and an arm 154 which has a bent end 156 which engages
the forked end 64 of lever 60. Spring 150 is biased to urge the
lever 60 towards the sector member 80.
A centering spring 160 has a coil and arms 162 and 164 which extend
through slot 21 of wall 14 of housing 12 and slot 100 of sector
member 80. The arms 162 and 164 are biased to spread or move away
from each other. Thus, the spring 160, when installed in the slots
21 and 100, will function to urge the sector member 80 to a
centered position with respect to the housing 12. Thus, springs 142
and 160 will cooperate to urge the lever 60 to a position wherein
magnet carrier 68 is in registry with opening 86 of the sector
member 80, and so that the arm 56 will normally be in engagement
with the neutral start switch 33.
As best seen in FIG. 4B, a park engagement spring 170 is attached,
by means of a cap screw for example (not shown), to a built-up
portion 172 formed on the underside of guide plate 22.
Mode of Operation
When not being manipulated by an operator, the lever 60 is normally
urged by springs 142 and 150 to a neutral position wherein shaft 66
is in neutral slot 38, between main slot 26 and park slot 32. In
this position the neutral start switch 33 is actuated by arm
56.
The lever 60 may be moved to the left, to the position shown in
FIG. 2, wherein the shaft 66 is moved into the park slot 32, magnet
carrier 68 moves into opening 86 in sector member 80, magnet 70
actuates Hall effect park switch 128, and detent spring 72
cooperates with detent member 98 to releasably hold lever 60 in
this position.
From this position, the lever 60 may be moved forwardly (or
upwardly viewing FIG. 2), wherein the sector member 80 moves with
the shaft 66, and magnet 102 actuates Hall effect switch 130. At
this point, spring 170 cooperates with shaft 66 to releasably hold
lever 60 in this position. The actuation of switch 128, followed by
actuation of switch 130 may be utilized to cause a
microprocessor-based electronic control unit (not shown) to place a
powershift transmission (not shown) in a park condition.
From the first described position, the lever 60 may be moved right,
forwardly and left (or right, upwardly and left viewing FIG. 2),
into reverse slot 30 via slot 36, at which point magnet carrier 68
moves into opening 84 in sector member 80, magnet 70 actuates Hall
effect reverse switch 126 and "not neutral" switch 124, and detent
spring 72 cooperates with detent member 96 to releasably hold lever
60 within reverse slot 30. If the lever 60 is then moved
rearwardly, the sector member 80 moves rearwardly with the shaft
66, and magnet 102 actuates Hall effect "bump shift" switch 134 and
deactuates switch 132. If the lever 60 is moved forwardly, the
sector member 80 moves forwardly with the shaft 66, and magnet 102
actuates Hall effect "bump shift" switch 130 and deactuates switch
132. If the lever 60 is released spring 160 will return sector
member 80 and lever 60 to a centered position with respect to
reverse slot 30 and actuates only switch 132. The actuation of
switches 130, 132 and 134 may be utilized to cause the
microprocessor-based electronic control unit (not shown) to upshift
or downshift the powershift transmission (not shown) among its
reverse gear ratios, enabled by actuation of switches 124 and
126.
From the first described position, the lever 60 may be moved right,
further forwardly and left (or right, upwardly and left viewing
FIG. 2), into forward slot 28 via slot 34, at which point magnet
carrier 68 moves into opening 82 in sector member 80, magnet 70
actuates Hall effect forward switch 120 and "not neutral" switch
122, and detent spring 72 cooperates with detent member 94 to
releasably hold lever 60 within forward slot 28. If the lever 60 is
then moved rearwardly, the sector member 80 moves rearwardly with
the shaft 66, and magnet 102 actuates Hall effect "bump shift"
switch 134 and deactuates switch 132. If the lever 60 is moved
forwardly, the sector member 80 moves forwardly with the shaft 66,
and magnet 102 actuates Hall effect "bump shift" switch 130 and
deactuates switch 132. If the lever 60 is released spring 160 will
return sector member 80 and lever 60 to a centered position with
respect to forward slot 28, actuating only switch 132. The
actuation of switches 130, 132 and 134 may be utilized to cause the
microprocessor-based electronic control unit (not shown) to upshift
or downshift, respectively, the powershift transmission (not shown)
among its forward gear ratios, enabled by switches 120 and 122.
Preferably, this shift lever assembly 10 would be mounted in a cab
of a vehicle (not shown) and oriented so that the long dimension of
the main slot 26 and the sub-slots 28, 30 and 32 would be
approximately parallel to the fore-and-aft direction of vehicle
travel.
While the present invention has been described in conjunction with
a specific embodiment, it is understood that many alternatives,
modifications and variations will be apparent to those skilled in
the art in light of the foregoing description. Accordingly, this
invention is intended to embrace all such alternatives,
modifications and variations which fall within the spirit and scope
of the appended claims. For example, the Hall effect devices could
be replaced with commercially available snap action switches or
with variable reluctance devices. Also, potentiometer type,
variable transformer or other conventional displacement type
transducers could be used to sense the positions of the lever in
place of the Hall effect devices.
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